Automotive vehicles are widely used to tow trailers such as vehicle trailers and recreational vehicles. Trailers typically use a trailer hitch that connects a trailer to a passenger car or truck as a tow vehicle. Trailer hitches include a tow ball that is installed on the tow vehicle and a draw bar that is integral to the trailer. The draw bar includes a socket that is received on and rotates against the tow ball, thereby allowing relative motion between the trailer and the tow vehicle during forward and reverse turning maneuvers.
Some recreational vehicles use a fifth wheel hitch that connects a recreational vehicle with a pickup truck as a tow vehicle. Fifth wheel hitches include a horseshoe-shaped member that is typically installed in a bed of the pickup truck and a tongue that is installed on the recreational vehicle. The tongue includes a coupling pin that is received within a slot defined by the horseshoe-shaped member. The tongue rotates against a horizontal surface of the horseshoe-shaped member, thereby allowing relative motion between the pickup truck and the recreational vehicle during forward and reverse turning maneuvers.
Negotiating a tow vehicle when coupled to a trailer can be particularly difficult, especially in reverse turning maneuvers, and can give rise to a particular problem commonly referred to as a jackknife situation. Jackknife situations arise when the tow vehicle is turned too sharply and a forward portion of the trailer collides with a rear portion of the tow vehicle. Collisions can cause significant damage to the tow vehicle and the trailer and may jar the two, presenting a hazardous situation.
Warning systems have been developed to warn a driver of an impending jackknife situation. However, jackknife warning systems developed for passenger cars and trucks as tow vehicles are typically designed for use with tow hitches and, therefore, are not easily adapted to fifth wheel hitches. Jackknife warning systems have been developed for use with fifth wheel hitches, however, these jackknife warning systems are typically designed for commercial truck and trailer combinations and, therefore, are not easily adapted to pickup truck and recreational vehicle combinations. Accordingly, there is a need to provide a jackknife warning system for fifth wheel hitches designed for use with pickup trucks and recreational vehicle combinations.
In accordance with the present invention, an alarm system for an articulated vehicle is provided. In one aspect, the alarm system includes a conductive post that extends vertically between two electrical contacts and a pair of arms that extend horizontally towards the post. The arms are disposed to move the post into contact with the electrical contacts when the articulated vehicle is turned at a radius that is too sharp, completing an alarm circuit and triggering an alarm. Additional aspects employ a mounting member that allows a first angle between the arms and a second angle of the arms with respect to a horizontal plane to be adjusted. In further aspects, the mounting member allows the arms to move together between a first position in which the arms extend towards the post and a second position in which the arms extend away from the post.
The present alarm system is advantageous over other alarm systems. For example, the alarm system is advantageously simple in construction and can be readily installed to a variety of commercially-available vehicle hitches, including fifth wheel hitches. The alarm system also advantageously allows the driver to set an alarm to trigger at his or her preference, and to position parts of the alarm system out of the way when hitching and unhitching. Additional advantages and features of the present invention will be found in the following description and accompanying claims, as well as in the appended drawings.
Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.